1. Field of the Invention
The invention relates to a flywheel/clutch arrangement for manual-shift synchronized change-speed gearboxes, in particular for motor vehicles having a planetary gear unit.
2. Description of the Prior Art
A flywheel/clutch arrangement of this kind is disclosed in U.S. Pat. No. 4,676,121 ('121). In the arrangement of the '121 patent, a flywheel is carried rotatably on a sleeve input shaft of the change-speed gearbox to which the clutch friction plate is non-rotatably connected and on which the input pinion of the change-speed gearbox is formed. The output shaft of the change-speed gearbox is connected to a sun gear of a planetary gearset. The output shaft is mounted concentrically within the input shaft, and rotates at a variable speed dependent on which gear ratio is currently engaged. The output shaft acts on the planetary gear unit through the sun gear, and thus affects the current speed of rotation of the flywheel.
The purpose of the '121 flywheel/clutch arrangement is to increase the mass moment of inertia of the flywheel/clutch arrangement when idling, and correspondingly decrease the inertia at higher vehicle speeds.
In the arrangement of the '121 patent, torsional vibrations arising from the internal combustion engine while idling are compensated by the high moment of inertia of the flywheel/clutch arrangement, whereby annoying rattling noises in the change-speed gearbox when idling can be avoided. On progressive shifting through the various gear ratios the mass moment of inertia of the flywheel/clutch arrangement is reduced stepwise by the falling speed of rotation of the sun gear connected to the output shaft, so that a quicker response of the internal combustion engine is obtained when demands are made on its performance by the driver.
While the known flywheel/clutch arrangement provides a way of affecting the mass inertial behaviour of such an arrangement, the clutch 10 of the '121 patent is directly connected to the input shaft 9 of the change speed gearbox. Therefore the work of synchronization required includes the mass of the clutch and causes high efforts in shifting the gearbox. It would be desirable to reduce the synchronization efforts of such an arrangement.